1. Field of the Invention
This invention relates to an improved device for mounting a plastic neck on containers made of a glass. In particular, the invention relates to a plastic neck with a resiliently deformable end that is adapted to snap onto a pre-manufactured vial-like glass bottle and a substantially non-deformable ferrule secured over the deformable end of the neck to retain it on the bottle.
2. Description of the Prior Art
For the display and storage of a variety of products, containers made of glass are preferred over containers made from plastic or other materials. For example, glass containers are often favored for storing cosmetic and pharmaceutical products because glass is known to be impermeable, chemically inert, stable and compatible with a variety of products. Glass containers can be produced in a variety of esthetically appealing colors, shapes and designs. As a material for making containers, glass offers excellent optical clarity that facilitates display of the contents of a bottle.
However, glass bottles generally cannot be produced at a low cost with certain desirable structural details, such as, for example, precise tolerances, detailed or sharp geometry and fine threads. Such structural details yield packages that are more attractive and perform better (e.g., open and close more conveniently and seal the contents more tightly against contamination and/or deterioration) than less detailed structure typically found on low cost glass containers. Thus, these structural details are associated with higher quality and higher cost packaging, i.e., xe2x80x98high-endxe2x80x99 packaging, such as, for example, packaging for pharmaceuticals and high-end cosmetics. As a particular example, these structural details are desirable for high-end mascara packages to securely attach a typical wiper and a typical combination applicator brush and closure cap.
Vial-like glass bottles are an example of a type of glass bottle that may be mass-produced at a low cost. A typical vial-like glass bottle is made, for example, by post forming an extruded glass tube. After extrusion, the glass tube is maintained at a temperature that allows it to be post-formed, or, if already cooled, is re-heated to a temperature that permits post-forming. The extruded tube is cut to a desired length. One end of the cut length of tube is pinched, pressed in a die or otherwise worked to form a closed end. The opposite end of the cut length of tube, i.e., the end with an opening, is roll formed on a die, or otherwise worked, to shape the opening and to provide a flange about the opening. The techniques for mass producing vial-like glass bottles are well known. Because this type of bottle is made from glass, low in cost and abundant in supply, it is a desirable container.
While offering at least the foregoing advantages, mass-produced vial-like glass bottles have several disadvantages. For example, the precise tolerances, detailed or sharp geometry, or the fine threads preferred for esthetically and functionally superior packaging cannot be provided to these bottles at a low cost. Although low cost vial-like glass bottles generally have a neck ring or flange on the neck adjacent to the bottle opening, dimensional tolerances for the bottleneck and flange are relatively large when compared to mass-produced containers made from other materials, such as, for example, plastic.
Plastic can be molded in a minimum number of manufacturing steps to significantly precise tolerances at a low cost. Thus, plastic is an ideal material for forming, for example, a bottle with a finely threaded neck. However, plastic packaging generally does not afford the same utility or marketing appeal as glass packaging because it may not be as impermeable, chemically inert, stable and compatible with a variety of products as glass, and may not offer the optical clarity of glass. Furthermore, the perception that a plastic container is a xe2x80x98cheapxe2x80x99 substitute for a glass container can negatively impact the marketability of the contents of the container.
An ideal container would offer the advantages of a glass container combined with the advantages of a plastic neck. Containers are known that provide the benefits of a plastic neck to a mass-produced glass bottle by attaching the plastic neck to the bottle. In the known constructions, the plastic neck is generally attached by relatively complex and costly manufacturing steps, such as, for example, adhering or crimping. These attachment methods can add significantly to per unit cost of producing a two part container.
U.S. Pat. No. 4,773,553 to Van Brocklin discloses dispenser including a plastic sleeve for mounting on a flanged container. The plastic sleeve has spaced tabs that are initially radially outwardly positioned, but that can be deformed radially inwardly beneath the flange of the container by a mounting cup (a ferrule). A drawback with this arrangement is that the mounting cap must have sufficient strength to deform the tabs and hold them securely in the deformed position. Also, variations in the degree and direction of deformation of the tabs may require the provision of tabs or a cap having dimensions and strength sufficiently large to compensate for such variations. These considerations would in turn yield a plastic sleeve and/or a cup with dimensions (e.g., thickness, length, etc.) that are undesirably large, particularly for a relatively small package, such as, for example, a mascara package. Also, the mounting cup has a sharp lower edge that could cause discomfort or even injury to the user, a drawback for a consumer oriented package.
U.S. Pat. No. 5,562,219 to de Pous et al. discloses a device for attaching a dispenser member to a receptacle. The device includes an attaching ring, a bottom portion of which is provided with snap-fastening tabs for fixing the ring to the neck of the receptacle. A hoop is provided to prevent tabs from splaying apart, thus, it is said, ensuring that the ring will remain fixed or attached. The hoop can be provided with one or more projections on the inside face, which may be defined by the convex side of an indentation formed in the wall of the hoop. A drawback of this arrangement is that the indentation in the wall of the hoop may undesirably impact the external appearance of a finished package. Another drawback of this arrangement is that the hoop appears to rely on the frictional interference fit between the projections and the plastic ring, but is not otherwise securely locked to the ring.
Also known are containers having a plastic cap attached to a bottle by a collar. For example, U.S. Pat. No. 5,857,579 discloses a plastic cap with a skirt that is snap fit onto the open end of a bottle. A collar, which may be made of a more rigid material than the cap, is placed over the skirt to enhance the points of contact between the cap and the container. However, the cap is applied directly to the container, and a neck with detailed or sharp geometry, fine threads, close dimensional tolerances or resilient sealing surfaces that would support, for example, the cap and applicator of a mascara package, is not disclosed.
Thus, there is need for a two part container made from a mass produced glass bottle with a plastic neck attached securely by simple, cost effective means, such that the container is air tight, and such the plastic neck can support detailed or sharp geometry, fine threads, close dimensional tolerances and/or resilient sealing surfaces.
The present invention is directed to an assembly for mounting a plastic neck on a vial-like mass produced glass bottle, and a simple, low cost method for securely mounting the plastic neck to the glass bottle. The glass bottle has an open end or neck with a flange or a downwardly directed annularly arranged shoulder. A plastic neck member is provided that has a first threaded end for receiving a cap, or a cap and dispenser combination. A second resilient end of the neck member has a sleeve adapted and dimensioned to snap fit onto the open end of the glass bottle by engaging the annular shoulder. The sleeve has a downwardly directed edge in an outer surface. A ferrule, preferably of metal, is press fit over the sleeve to lock the neck member onto the glass bottle. The ferrule has an upwardly directed edge that engages the downwardly directed edge of the sleeve. The upwardly directed edge is preferably provided by folding a lower edge of the ferrule inwardly and upwardly to form an inner rim. During assembly, the ferrule is forced over the neck member until the inner rim snaps in below the downwardly directed edge of the neck member, thus locking the ferrule onto the neck member. A seal provided between the neck member and the bottle ensures that the connection of the plastic neck member to the glass bottle is airtight.